Stepdown fixes...
The purpose of the 5000 foot turn on is to separate you from the aircraft joining the ILS finals to the other two runways. The rule is you have to be level at the altitude, established on final, and on a frequency with final monitor override prior to losing 1000 feet separation with those on the adjacent finals. The "stepdown" or crossing altitudes at the other fixes are designed to separate you from those turning final to the other runways.
To answer your question, it is completely legal for you to descend to those altitudes on the plates as you would normally do with any stepdown fix... however, most controllers are going to expect you to fly at 5000 until you join the GS and then to descend according to it.
I do not work at KORD, but I did work at both KDFW and KIAH, and they both also had triple simultaneous ILS approaches to parallel runways, just as KORD and KATL do.
Safe Skies!!